ADS-B is a signal that commercial aircraft transmit that indicates their speed, position and heading, among other things.
To receive it you need an RTL-SDR receiver and some decoding software. I recently bought at dongle from NooElec, the NESDR SMArtee. One end plugs into a USB port on the computer and the other end attaches to an antenna.
It came in a bundle with some cheap antennas for listening to broadcast radio as well as one that’s tuned to 1090 Mhz where the ADS-B broadcasts are located.
I installed software called dump1090 on my RPi 4B which decodes the signals from the aircraft and plots them on a map (see below). Pretty cool.
I also installed PiAware which connects to the FlightAware website and transmits the data received to them, which they use to track aircraft all over the world and display on their website. In exchange for feeding them data FlightAware offers a free premium subscription.
I had a problem with the PiAware installation and I don’t have it working properly yet, so I’m not able to connect to FlightAware. But I have noticed that my data is more up to date than what is displayed on the FlightAware website.
But you can see from the screen capture below that I am getting some good data from the aircraft in the area. We live in a busy air traffic area, so this should be interesting.